Previous efforts to make transparent alumina centered about hot pressing and sintering processes. Patents illustrating the latter technique are the Coble U.S. Pat. No. 3,026,210 and the St. Pierre et al U.S. Pat. No. 3,026,177. The Coble and St. Pierre materials are dense polycrystalline structures having coarse equiaxed grains of about 20-150 microns in diameter.